1. Technical Field
This disclosure relates to an extreme ultraviolet (EUV) light generation system for generating extreme ultraviolet light.
2. Related Art
With recent increase in integration of semiconductor process, transfer patterns for use in photolithography of the semiconductor process have rapidly become finer. In the next generation, microfabrication at 70 to 45 nm, further, microfabrication at 32 nm or less is to be demanded. Accordingly, to meet the demand for microfabrication at 32 nm or less, for example, an exposure apparatus is expected to be developed, where EUV light at a wavelength of approximately 13 nm is combined with a reduction projection reflective optical system.
There are mainly three types of known EUV light generation systems, namely, a laser produced plasma (LPP) type apparatus using plasma generated as a target material is irradiated with a laser beam, a discharge produced plasma (DPP) type apparatus using plasma generated by discharge, and a synchrotron radiation (SR) type apparatus using orbital radiation.